Piston



April 7, 1925.

v A. l.. ARMENTROUT PISTON Filed May v, 1925 ATTOR Patented Apr. 7, 1925.

UNITED STATES ARTHUR LEON ARMENTROUT, 0F WLITTIER, CALIFORNIA, ASSIGNOR OF ONE-HALF TO THE GUDBERSON WARE.

PISTON.

Application nled May 7,

To all whom t may cof/wem:

Be it known that I, ARTHUR LEON ARMEN- TRoU'r, a citizen of the United States, and a resident of Whittier, county 'of Los Angeles, and State of California, have invented a new and useful Piston, of which the following is a specification.

The present invention'relates to improvements in pistons reciprocating in cylinders and its particular object is to provide means in connection with a piston that will prevent a pressure medium actuating the piston or actuated by the piston from leaking past the piston. My improvement has particular reference to a-nd will be described in connection with a pump and more particularly a force or pressure pump although not confined to that particular device. It is proposed in the present invention to utilize the pressure of the medium acted on for effecting a pressure-tight engagement between a circumferential ring or sleeve on the piston and the wall of the cylinder. More particularly it is proposed to allow the pressure medium acted on by the piston to pass underneath the ring so as to force the same away from its seat into engagement with the cylinder wall, an to furthermore provide a pumping mecha ism within the main piston adapted to be acted on by the pressure medium on the working stroke of the piston, and to force a charge of the pressure Inedium between the piston and the ring. It is further proposed to provide check valves within the passages allowing the pressure medium to enter underneath the piston ring so as to prevent the pressure medium from escaping on the inactive stroke of the main piston. Further objects and advantages will appear as the specification proceeds.

The preferred form of my invention-is illustrated in the accompanying drawing in which Figure 1 shows a longitudinal' section through a pump using my piston; Figure 2 a: longitudinal section throu h the pis-- ton itself taken along line 2-2' ofg Figure 3; Figure 3 an end view of the piston as viewed from the right hand side with certain portions shown broken away and Figure 4 a sectional view similar to that of Figure 2v with the main working unit shown in4 side elevation. While I have shown only the preferred form of my invention, it should be understood that various changes or modifications may be made within the scope of the 1923. Serial No. 637,312.

claims hereto attached without departing from the spirit of the invention.

In Figure 1 is shown the cylinder (1) of any suitable type of continuousdelivery force pump with a piston (2) on the pump rod (3) reciprocating therein. On a stroke to the left a fluid medium such as water is drawn into the cylinder through a port (4) CORPORATION, 0F DALLAS, TEXAS, A CORPORATION OF DELA- and delivered through the port (6), while wheny the piston moves to the right the liquid medium is forced outwardly through the port (4) and sucked into the cylinder through the port (6). A valve mechanism not shown in the dra-wing allows of this o eration. l The principal feature of present invention is the construction of the 'piston (2). The latter comprises a cylinder (7) confined betweentwo discs (8) and (9), which latter are forced upon the cylinder in any suitable manner, as for instance by means of the bolts (11) engaging their threaded ends, with the heads of the bolts and the nuts disposed on opposite sides of the two discs. The cylinder (7) is surrounded by a plurality of rings (13), ref` erably three iii number, which are ma e of yielding material such as rubber for instance, and disposed in adjacent relation in such a manner as to slightly project circumferentially beyond the discs (8) and (9).

The piston rod (3) is reduced in diameter to form a shoulder (14) and is tapered beginning from said shoulder as shown at (15) to engage a bushing (.16) disposed between the two discs. (8) and (9). It is held in Y, place by means of the nut- 17) which latter 1s locked against rotation y a second nut (18). A heavy ringZ (19) fills the space between ,the cylinder and the bushing (16) and is provided with a plurality of recesses (22) inserted therein by means of a threa ed engagement. (23). Preferably four of these plugs are provided in s mmetrical arrangement at either end eac two lu in o posite ends being axially alineg. gvallie `p ugs are recessed again as shown at (24) and receive the plungers (26) which are,

limited in` their outward motion by `means of externally threaded nuts (27) threadedly lengaging the plugs (22 The s ri ngs`(2 8),

bearing at one end on s oulders 29) formed in the plugs and atthe other end on shoulders (31) 'formed on the pistons, tend to force the plungers (26) upon the nuts (27).

05 in either end adapted to have plu s i tial grooves (36).

The inner ends of the plungers, which are reduced to form the shoulders (31), are adapted' to slide into a reduced portion of the recess in the plugs (22). i

The reduced recess in the inner end of each plug connects with `a perforation' (32) of the same diameter, which latter perforation extends through that portion of -the ring (19) not occupied by the two opposing plugs and the center of said recess communicates with a Yradial passage (33) leading into a longitudinal slot (34) in the cylinder (7), which latter slot connects with a plurality of circumferential grooves (36)', each groove being disposed centrally under one of the rings (13). Corresponding central perforations in the plugs (22), the nut (27) and the discs (8) and (9) open a continuous passage from the exterior into the recess (32) connecting through the ports (33) with longitudinal slots (34) andthe circumferen- The longitudinal part of each passage is controlled ty means of two "spring actuated check valves (37) and (38),

which allow the liquid medium to enter into the piston but prevent the same Afrom Howing backward. The radial port (33) which communicates with two of the longitudinal passages isalso controlled by a check valve rlthe operation of this'pist-on may li-d6- serihed as follows: When the piston as viewed in Figurel moves to the right Yso as to force a ohargethrough the port (d) and F' to draw in a charge through the port (6),

the left hand plunger (26) is forced upon its seat hy the spring (28) and liquid enters through the check valve (37) -into the interior of the plunger, which liquid, on the next left hand stroke, is forced through the check valves (38) into the chamber formed hy thevrece'ss (32), the port (33), the slots (34) and the grooves (36). 0n' thesiame stroke the right hand end of the main pis-V ton (2) Yforces the liquid outwardly and the liquid "hearing on the plunger (26) on the right hand side forces the same inwardly so as to orce its charge collected during 'the previous stroke through the check valve (38) into the chamber previously described, with the result that the additional liquid forced into the chamber lifts the central peripheral portions of the three flexible rings (13) ofi their seats and into close contact with the wall of the cylinder. On a left hand stroke, the left end of the piston hecomes the pressure side, and the left hand 'plunger (26) delivers itsy charge to the chamber, while the right handA plunger is seated by its operation (28) and draws in a new charge, so that the same result is oh- Vtained whether the piston moves to the right or to the left, the check valves preventing the `liquid from dowi'ng hackwardly.

Particular attention is called to the fact that the actual force brought to bear on the thousand pounds per unit area, the same lpressure will be exerted on the liquid in the chamber. It the exposed portion of the outer face is less than the inner face of the plunger (26) the pressure on the liquid in the chamber' will be decreased accordingly, while when the exposed part of the outer face is larger than the'inner face of the piston, the pressure will be increased, so that the dimensions for the piston may be selected to suit conditions. rlhis is particularly desirable where the pressure within the cylinder is so high that a full'application of the .pressure-would prove destructive to the piston.

l claim: Y

1. ln a pressure pump havingacylinder and a piston reciprocating therein, an expansible wall engaging element on the piston and a pumping mechanism within the Vpiston actuated by the pump pressure for on the working stroke of the piston.

2. ln a pressurepump having a cylinder` and a piston reciprocating therein, an expansible wall engaging element on'the piston and a plunger adapted to reciprocate in the piston parallel to its axis made to receive a charge on the inactive stroke of the piston and to deliver the same to the expansible element for forcing the latter against the wall on the working stroke.

3. ln a reciprocating piston of the cha-racter described having pressure strokes altermating withn suction strokes, an expansihle ring element surrounding the piston and a pump mechanism with the piston adapted to receive a charge of a pressure medium on the suction stroke and to deliver the same toi the ring element on the pressure stroke for expanding the latter. l

d. lin a reciprocating piston of the character described having pressure strokes alternating with suction strokes, an expansible.

ring element surrounding the piston and a pump mechanlsm with the piston adapted to receive a charge of a pressure medium on .casacca acter described having pressure strokes alternating with suction strokes, an expansible ring element surrounding the piston Vand a pump mechanism Wit-hin the piston adapted to receive a charge of a 'pressure medium on the suction stroke and to deliver the same to the ring element on the pressure stroke for expanding the latter, comprising a longitudinal passage in the piston communicating with the inner face of the ring, a valved plunfrer slidable Within said passage and spring means for seating the plunger oii the suction stroke.

6. in a reciprocating piston of the character described having pressure strokes alternating with suction strokes, an4 expansible 'ring element surrounding the piston and a pump mechanism with the piston adapted to receive a charge of a pressure medium on the suction stroke and to deliver the saine to the ring element on the pressure stroke for expanding the latter, comprising a longitudinal passage in the piston coniiiiunicat-ing with the inner face of the ring, a valved plunger slidable Within said passage and a second val-ve in the passage for preventing back flow on the suction stroke.

7. ln a double-acting,'reciprocating piston of the character described having pressure stiolres alterna-ting with suction strokes at either end, an expansible rinlg element surrounding the piston and axial y alined pump inechanisms'in either end of the piston, each adapted to receive a charge of a pressure medium on the suction stroke and to deliver the saine on the pressure stroke to the ring clement for expanding the latter.

8. in a double-acting reciprocating piston of the character described having pressure strokes alternating with suction strokes at either end, an expansible ring element suri'ouiidiiio the piston and axially alined pump mechanisms in either end of the piston, each adapted to receive a charge of a pressure SEB medium on the suction stroke and to deliver the saine on the pressure stroke to the ring element for expanding the latter; the pump mechanisms comprising alined longitudinal passages in the piston having a common coininunication with the inner tace of the ring element and valved plungers slidable Within the same.

9. ln a double-acting reciprocating piston of the character described having pressure strokes alternating with suction strokes atv either en'd. an expansible ring element surrounding tlie piston and axially alined pump mechanism in either end of the piston, each adapted to receive a charge of a pressure medium on the suction stroke and to deliver the saine on the pressure stroke to the ring element ttor expanding the latter, the pump mechanisms comprising alined longitudinal passages in the piston having a coininon communication with the inner face of the ring, valved plungers slidal'ile 'Within the saine and a second valve in each passage for preventing hack flow on the suction strokes.

l0. ln a double-acting reciprocating piston of the character described having pressure strokes alternating with suction strokes at either end, an expansiblering element surrounding the 'piston and axially alined pump mechanisms in either end of the piston, each adapted to receive a charge of a pressure medium on the suction stroke and to deliver the same on the pressure stroke to the ring element for expanding the latter, the pump `mechanisms comprising alined .longitudinal saine, a second -valve iii each passage for preventing back flow on the suction stroke and a third cfhecl: valve in the common coniinunication.

ARTHUR LEON ARISLENTROUT. 

